Exogenous Abscisic Acid and Its Effect on Seed Germination of Wheat and Triticale

The effects of exogenous abscisic acid (ABA) on early germination processes in seeds of two cereal crops, wheat and triticale (a hybrid of wheat and rye), are investigated. A clear relationship was established between growth processes and both the concentration of ABA and the imbibition stage at which ABA was applied. At moderate to high concentrations (10–6–10–4 M), ABA acted as an inhibitor of physiological processes. Early stages of seed germination, specifically those involving physical swelling and radicle emergence, were found to be highly sensitive to ABA. Furthermore, a high concentration of exogenous ABA (10–4 M) inhibited the mobilization of protein reserves in the wheat embryo, which may contribute to the overall inhibition of germination.